import os
from tkinter import filedialog
from PIL import Image
from future.moves import tkinter


def open_img():
    """
    打开图片
    :return:
    """
    root = tkinter.Tk()  # 创建一个Tkinter.Tk()实例
    root.withdraw()  # 将Tkinter.Tk()实例隐藏
    default_dir = r"文件路径"
    file_path = filedialog.askopenfilename(
        title=u'选择文件', initialdir=(os.path.expanduser(default_dir)))
    if len(file_path) != 0:
        image = Image.open(file_path)
        fill_image(image)
    else:
        SystemExit()


def fill_image(img):
    """
    将图片填充为正方形
    :param img: 图片
    :return:
    """
    width, height = img.size
    # 选取长和宽中较大值作为新图片的
    new_image_length = width if width > height else height
    # 生成新图片[白底]
    new_image = Image.new(
        img.mode, (new_image_length, new_image_length), color='white')
    # 将之前的图粘贴在新图上，居中
    if width > height:  # 原图宽大于高，则填充图片的竖直维度
        # (x,y)二元组表示粘贴上图相对下图的起始位置
        new_image.paste(img, (0, int((new_image_length - height) / 2)))
    else:
        new_image.paste(img, (int((new_image_length - width) / 2), 0))
    cut_image(new_image)


def cut_image(img):
    """
    切图
    :param img: 填充成方形后的图片
    :return:
    """
    width, height = img.size
    item_width = int(width / 3)
    box_list = []
    for i in range(0, 3):  # 两重循环，生成9张图片基于原图的位置
        for j in range(0, 3):
            box = (j * item_width, i * item_width, (j + 1)
                   * item_width, (i + 1) * item_width)
            box_list.append(box)

    img_list = [img.crop(box) for box in box_list]
    save_images(img_list)


def save_images(img_list):
    """
    保存切割完成的图片
    :param img_list: 切割后的图片列表
    :return:
    """
    index = 1
    files_path = 'Pic'
    # 若文件夹不存在，则创建
    if not os.path.exists(files_path):
        os.makedirs(files_path)

    for img in img_list:
        img.save('./Pic/' + str(index) + '.png', 'PNG')
        index += 1
    print('完成')


if __name__ == '__main__':
    open_img()
